1. Field of the Invention
The present invention relates to a method for obtaining pure copper. More specifically, in the method, oxygen is blown onto a copper melt, in a melting furnace lined with refractory material, having a waste heat boiler set onto it, in order to oxidize contaminants contained in the melt and thereby remove them from the melt. In addition, a splash protection device through which water flows is provided above the copper melt, on the inside wall of the melting furnace. The splash protection device prevents copper that splashes out of the copper melt from penetrating into the waste heat boiler.
2. The Prior Art
Methods having the characteristics described above are known in practice. The splash protection device, which is frequently also referred to as a so-called splash block, generally is made of copper. The splash protection device is necessary because moisture that is introduced into the melt together with the oxygen, for example, through a lance, evaporates explosively and entrains liquid copper a long way upward with it, as it explodes. The splash block, which is attached to the inside wall of the melting furnace, below the waste heat boiler, prevents the entry of drops of melt into the waste heat boiler, and protects the boiler from an inside coating of solidified copper.
Within the scope of the known measures, the splash block has pipes that are made of copper, for guiding a non-pre-heated cooling water, which pipes are cast into a copper block. However, although melting of the copper is effectively prevented by means of the cold cooling water, erosion corrosion takes place at the copper block, because of sulfur contained in the copper melt. As a result, it becomes necessary to replace the splash block after only a few months. Another problem is that if a crack caused by corrosion phenomena occurs in the splash block, cold cooling water penetrates into the copper melt. The water evaporates explosively there and thereby results in a massive impact of solidifying copper splashed out of the melt against the waste heat boiler.
DE 100 47 555 A1 describes a cover for a metallurgical melting furnace, which cover has cooling channels through which cold water flows. Furthermore, it is known from the German Offenlegungsschrift D 13484 VI/18b to use boiling water for cooling chimney walls, and to use the evaporation enthalpy for cooling. The water is passed along the chimney wall in long, vertical riser lines. Because of the great height of the chimney, a vigorous water circulation occurs in the riser lines, in this connection, allowing effective cooling of the chimney wall. The measures described in the Offenlegungsschrift do not make any contribution toward solving the set of problems described above.